In the production of a fluorescent lamp the conventional manner for producing the elongated tubular glass envelopes in finished form so that they can proceed to the phosphor coating stage of the production process, involves first pulling from a glass furnace a long continuous glass tube which may extend for several hundred feet until it is cool enough to be processed. This elongated glass tube is cut in lengths which are slightly oversized with respect to the final lamp length and are dropped onto a conveyor belt which carries them in parallel relationship and on which they are cut to their final length. These parallel moving glass tubes are then picked up individually adjacent each end by an end-forming machine which includes a pair of spaced indexing turrets which move the glass tubes through six work stations which reciprocate onto each end of the tube as it indexes through the end-forming machine. The first five work stations are merely heating fires which soften the glass, with the sixth being an end-forming die which reciprocates in and closes to neck down each end of the glass tube simultaneously. At the next index of the indexing turrets the glass bulbs are released onto a second parallel conveyor where they move to a boxing station at which point they are placed in boxes for storage until they are to be manufactured into completed fluorescent lamps.
End-forming machines in the past have included a pair of spaced indexing turrets which carried the glass tubes through the end-forming operations as hereinbefore described. These spaced indexing turrets were fixed to a single shaft which interconnected the two turrets at the centers thereof. This central shaft also carried thereon the forming tools in the form of the gas fires and the forming die. When it was desired to change the length of tube being operated upon by the end-forming machine, it was necessary to shut the machine down, unbolt one of the indexing turrets and its associated tooling from the shaft, move these parts along the shaft to the new position which would accommodate the new length of tubing which was to have its ends formed and then the indexing turret and its associated tooling would have to be resecured to the rotating shaft. Many times, the machine would be down for several hours while precise alignment between the two indexing turrets was achieved because of the criticality of the relationship between the two turrets which generally index at a rate of about 90 indexes per minute. Many problems evolve from improper alignment such as the inability of the two turrets to simultaneously pick up each end of the glass tube as well as the problem of torque being applied at opposite ends of the thin walled glass tubing. With separately movable tooling the tooling had to be also remounted to the shaft at a position which left it identically spaced with respect to the turret as it was when the previous sized tubing was being end-formed.